<!doctype html>
<html>

<head>
    <meta charset="utf-8">
    <title>float:left水平排列</title>
    <style>
        .float-left {
            float: left;
            border: 1px solid yellowgreen;
            width: 200px;
            height: 120px;
            margin: 10px;
        }

        .clear {
            clear: both;
        }
    </style>
</head>

<body>
    <div>
        <div class="float-left">4</div>
        <div class="float-left">5</div>
        <div class="float-left">6</div>
    </div>
    <div class="clear"></div>
</body>

</html>